1. Field of the Invention
The present invention relates to a friction disc, especially for a motor vehicle clutch.
2. Description of Related Art
More particularly the invention is concerned with a friction disc of the same type as that described and shown in the document EP-A-0 579 554.
That document describes and shows a friction disc comprising a plate for supporting friction liners in the form of a ring, with its outer peripheral portion being divided into radial blades carrying friction liners which are arranged, in particular, axially on either side of the support plate, with each blade being of tripod type and having, by virtue of folds, a central engagement zone which is joined to the central portion of the plate, together with two peripheral engagement zones which are arranged tangentially on either side of the central engagement zone.
This design, in which the tripod type blades have a form which is generally symmetrical with respect to a radial axis of symmetry, enables the blades to have as great a resistance to centrifugal force as is desired, with the central engagement zone serving to fasten a first one of the friction liners, while the peripheral engagement zones are arranged to come into contact with the second one of the friction liners.
In addition, contact with, in particular, the pressure plate of the clutch is greatly improved by avoiding the situation where the zone in which the friction liners are subjected to the pressure from one or other of the two plates between which the friction disc is gripped, is displaced progressively towards the axis of the assembly, so wear in the friction liners is thus generally even and regular.
The design according to the prior art accordingly proposes a standard carrier disc for liners which is able to rotate at high speed while reducing seizing and jamming effects, and is at the same time capable of adopting a conical form.
The present invention is concerned with an improvement to a friction disc of the same type as that described and shown in the document EP-A-0 579 554, which in particular gives a further increase in the capacity to resist centrifugal force and/or to resist deformation resulting in variations in operating temperature, these effects most particularly affecting the peripheral engagement zones of each tripod type blade.